Plasma extracellular vesicle circRNA signature and resistance to abiraterone in metastatic castration-resistant prostate cancer.

BACKGROUND: We aimed to develop and validate a plasma extracellular vesicle circular RNA (circRNA)-based signature that can predict overall survival (OS) in first-line abiraterone therapy for metastatic castration-resistant prostate cancer (mCRPC) patients. METHODS: In total, 582 mCRPC patients undergoing first-line abiraterone therapy from four institutions were sorted by three phases. In the discovery phase, 30 plasma samples from 30 case-matched patients with or without early progression were obtained to generate circRNA expression profiles using RNA sequencing. In the training phase, differentially expressed circRNAs were examined using digital droplet PCR in a training cohort (n = 203). The circRNA signature was constructed using a least absolute shrinkage and selection operator Cox regression to predict OS. In the validation phase, the prognostic ability of this signature was prospectively validated in two external cohorts (Cohort I, n = 183; Cohort II, n = 166). RESULTS: We developed a five-circRNA signature, based on circCEP112, circFAM13A, circBRWD1, circVPS13C and circMACROD2, which successfully stratified patients into high-risk and low-risk groups. The prognostic ability of this signature was prospectively validated in two external cohorts (P < 0.0001, P < 0.0001). Patients with high-risk scores had shorter OS than patients with low-risk scores. CONCLUSION: This five-circRNA signature is a reliable predictor of OS for mCRPC patients undergoing abiraterone.

A urine extracellular vesicle circRNA classifier for detection of high-grade prostate cancer in patients with prostate-specific antigen 2-10 ng/mL at initial biopsy.

The aim of this study was to identify a urine extracellular vesicle circular RNA (circRNA) classifier that could detect high-grade prostate cancer (PCa) of Grade Group (GG) 2 or greater. For this purpose, we used RNA sequencing to identify candidate circRNAs from urinary extracellular vesicles from 11 patients with high-grade PCa and 11 case-matched patients with benign prostatic hyperplasia. Using ddPCR in a training cohort (n = 263), we built a urine extracellular vesicle circRNA classifier (Ccirc, containing circPDLIM5, circSCAF8, circPLXDC2, circSCAMP1, and circCCNT2), which was evaluated in two independent cohorts (n = 497, n = 505). Ccirc showed higher accuracy than two standard of care risk calculators (RCs) (PCPT-RC 2.0 and ERSPC-RC) in both the training cohort and the validation cohorts. In all three cohorts, this novel urine extracellular vesicle circRNA classifier plus RCs was statistically more predictive than RCs alone for predicting ≥ GG2 PCa. This assay, which does not require precollection digital rectal examination nor special handling, is repeatable, noninvasive, and can be easily implemented as part of the basic clinical workflow.

Prospective validation of DACH2 as a novel biomarker for prediction of metastasis and prognosis in muscle-invasive urothelial carcinoma of the bladder.

Metastasis is the main cause of death from muscle-invasive urothelial carcinoma of the bladder (UCB), and the metastatic potential of tumors is often unpredictable. The role of Dachshund homolog 2 gene (DACH2) in tumorigenesis remains unexplored. We aimed to investigate whether DACH2 can be used as a biomarker to predict metastasis and prognosis of muscle-invasive UCB in a sequential training and validation fashion. For the training set (n = 40), compared with UCB patients without lymph node (LN) metastasis, both DACH2 protein and mRNA expression were greatly increased in case-matched patients with LN metastasis. For the independent validation set (n = 243), patients with primary UCB that did not express DACH2 had a longer metastasis-free survival (MFS) and overall survival (OS) than did those with tumors expressing DACH2 (5-year MFS: 88% [95% CI 80-96] versus 19% [95% CI 7-31], p < 0.001; 5-year OS: 93% [95% CI 87-99] versus 37% [95% CI 23-51], p < 0.001). Multivariable analysis of DACH2 status showed hazard ratios of 7.34 (95% CI 3.15-11.87, p < 0.001) for MFS and 3.96 (95% CI 2.04-7.16, p < 0.001) for OS which were much higher than hazard ratios associated with other independent risk factors. Collectively, DACH2 is an independent prognostic marker that can be used at initial diagnosis of UCB to identify patients who have a high potential to develop metastasis.

A urine extracellular vesicle lncRNA classifier for high-grade prostate cancer and increased risk of progression: A multi-center study.

To construct a urine extracellular vesicle long non-coding RNA (lncRNA) classifier that can detect high-grade prostate cancer (PCa) of grade group 2 or greater and estimate the risk of progression during active surveillance, we identify high-grade PCa-specific lncRNAs by combined analyses of cohorts from TAHSY, TCGA, and the GEO database. We develop and validate a 3-lncRNA diagnostic model (Clnc, being made of AC015987.1, CTD-2589M5.4, RP11-363E6.3) that can detect high-grade PCa. Clnc shows higher accuracy than prostate cancer antigen 3 (PCA3), multiparametric magnetic resonance imaging (mpMRI), and two risk calculators (Prostate Cancer Prevention Trial [PCPT]-RC 2.0 and European Randomized Study of Screening for Prostate Cancer [ERSPC]-RC) in the training cohort (n = 350), two independent cohorts (n = 232; n = 251), and TCGA cohort (n = 499). In the prospective active surveillance cohort (n = 182), Clnc at diagnosis remains a powerful independent predictor for overall active surveillance progression. Thus, Clnc is a potential biomarker for high-grade PCa and can also serve as a biomarker for improved selection of candidates for active surveillance.

CircSCAF8 promotes growth and metastasis of prostate cancer through the circSCAF8-miR-140-3p/miR-335-LIF pathway.

Circular RNAs (circRNAs) have been increasingly linked to cancer progression. However, the detailed biological functions of circRNAs in prostate cancer (PCa) remain unclear. Using high-throughput circRNA sequencing, we previously identified 18 urine extracellular vesicle circRNAs that were increased in patients with PCa compared with those with benign prostatic hyperplasia. Spearman correlation analysis of the expression levels of the 18 circRNAs between the tumor tissue and matched urine extracellular vesicles in 30 PCa patients showed that circSCAF8 had the highest R2 (R2 = 0.635, P < 0.001). The Cox proportional hazards regression model was used to estimate the effect of circSCAF8 on progression-free survival. The in vitro and in vivo functional experiments were implemented to investigate the effects of circSCAF8 on the phenotype of PCa. We found that the knockdown of circSCAF8 in PCa cells suppressed the proliferation, migration, and invasion ability, while overexpression of circSCAF8 had the opposite effects. Similar results were observed in vivo. In a cohort of 85 patients who had undergone radical prostatectomy, circSCAF8 expression in PCa tissues was a powerful predictor of progression-free survival (HR = 2.14, P = 0.022). Mechanistically, circSCAF8 can function by binding to both miR-140-3p and miR-335 to regulate LIF expression and activate the LIF-STAT3 pathway that leads to the growth and metastasis of PCa. Collectively, our findings demonstrate that circSCAF8 contributes to PCa progression through the circSCAF8-miR-140-3p/miR-335-LIF pathway.